The characteristics of autism spectrum disorders (ASD) observed among relatives of people affected with autism are referred to as broader autism phenotype (BAP). Among the components of BAP are language and communication skills. Research to date on these skills amongst the relatives of individuals with ASD is inconclusive. Furthermore, limited data are available about preschool-aged siblings of children with ASD.

Participants and procedure

Eighty-six children aged 4 years and 6 months – 6 years and 11 months took part in the study (32 girls and 54 boys). They were divided into four groups: siblings of children with autism (S/ASD), high-functioning children diagnosed with autism spectrum disorders (HF/ASD), siblings of children with Down syndrome (S/DS) and siblings of typically developing children (Controls, C). Communication and language skills were tested using the Vocabulary Test for Children (TSD). It was used to assess two kinds of verbal skills: receptive language (passive) and expressive language (active).

Results

No differences were observed in expressive lanquage or receptive language between siblings of children with ASD and siblings of children with DS as well as typically developing children. In terms of receptive language and general communication skills, siblings of children with ASD scored higher than high functioning children with ASD. High functioning children with ASD displayed difficulties with receptive language, expressive language, general language and communication skills.

Conclusions

The results suggest that siblings of children with ASD do not display deficits in communication and language skills. It is however important to note that due to a small sample size this study should be considered as preliminary.